The present disclosure relates to rotary winged aircraft. More specifically, the present disclosure relates to health assessment of rotor systems of a rotary wing aircraft.
Unlike airframe airspeeds and inertial motion, there is limited visibility into specific loads and motions to which rotor system components are subjected. Such information would be useful for health assessment and management of the rotor system components, as well as for flight controls and as historical data for future design improvements.
Current practice in rotor health monitoring consists primarily of periodic visual inspections. These inspections are augmented with continuous rotor track and balance (RTB) monitoring in health and usage monitoring system (HUMS)-equipped rotorcraft. Physical sensors located within the rotating system would significantly enhance rotor health monitoring, thereby reducing the rotor system maintenance burden. Further, the ability to measure key rotor loads on operational rotorcraft would provide the data and insight that may lead to a radical change in the way rotorcraft are designed, qualified, and managed throughout their product life cycle.
The lack of such rotor system measurements is indicative of the perceived difficulties, increased weight, and reliability issues associated with deploying physical sensors within the rotor system and transferring power and data from/to the airframe. First, the use of a wired sensor system with a traditional slip ring, rotary transformer or fiber optic rotary joint to transfer data between rotating and fixed elements tends to be unreliable and requires high maintenance when deployed for long periods of time in harsh environments. Second, the fixed number of channels in these traditional systems limits scalability. Third, a wiring harness would be required to operate in this environment of moving components under forces that test the limits of shielding and connectors over prolonged periods of time.